When we took the engine apart at Coote's we replaced the rings with new Norton rings. I really needed to have pistons matched to the barrel too . Or new Barrel /pistons /rings . But we were not prepared with the parts for that , So , Just a New set of rings went in. It took nearly 3,000 miles to fully bed those new rings in . For now I am happy enough. In review the steps :
Tony,
I think the Factory had several issues with the piston ring on some machines.
I picked up my 2013 CR in December 2013 from my dealer. It smoked like crazy when started, and was really difficult to get started. Once warmed up the smoking stopped. I got a call from my dealer about 2 weeks later, he said he was sending a van to pickup my bike. He said that Norton informed him that my bike had incorrect parts installed, and that they would send a "repair" kit to the dealer to resolve the issue.
The dealer had to pull the head and barrels off, and check the bores.
I spoke to the mechanic about this when I picked the bike up and he told me some story:
1. The bores were fine, but the rings were too small and had too large of an end gap. The replacement rings were right on.
2. The "repair" kits also included new valve springs, and valve seals, collars. The originals were apparently the wrong spec and there was a threat of the springs binding.
3. There was no shop manual yet for the 961, so the "repair" was performed using FAX-ed hand written instructions and pencil sketches from the Factory.
There was no longer any smoke in the exhaust after the "repair", and starting was much easier.